Design of a theranostic Gd (III)–Cu (I) complex to inhibit growth and metastasis of triple-negative breast cancer

For precise personalized treatment of triple-negative breast cancer (TNBC) and inhibition of its metastasis, we innovatively designed and synthesized a gadolinium (III)–copper(I) complex (GdCu) with remarkable performance in T₁-weighted magnetic resonance imaging (MRI) and cytotoxicity to TNBC cells. In addition, we constructed a GdCu@apoferritin (AFt) nanoparticles (NPs) delivery system. GdCu and GdCu@AFt NPs significantly inhibited the migration and invasion of MDA-MB-231 cells in vitro. GdCu can significantly inhibit the growth and metastasis of TNBC in vivo. GdCu@AFt NPs not only improved the targeting ability of GdCu, showed an enhanced performance of MRI and tumor-growth inhibition, but also decreased the systemic toxicity of GdCu in vivo. We demonstrated that GdCu and GdCu@AFt NPs prevented the growth and metastasis of TNBC by inducing mitochondria-mediated apoptosis and inhibiting cancer cell stemness. The remarkable MRI, anticancer and anti-metastasis capabilities of GdCu and GdCu@AFt NPs make them promising agents for the targeted theranostics of TNBC.